Process of making alloy steel



JOHN MOCONNELL, OF'CHIGAGO, ILLINOIS, ASSIGNOR TO INTERSTATE IRON AND,

STEEL COMPANY, OF CHICAGO, ILLINOIS,

A CORPORATION OF ILLINOIS.

rnocnss or MAKING. ALLOY STEEL N 0 Drawing.

To all whom it may concern:

Be it known that I, JOHN MOCONNELL, a citizen of the United States,residing at Chicago, in the county of Cook, State of Illinois, havinginvented certain new and useful Improvements in. Processes of MakingAlloy Steel, do hereby declare that the following is a full, clear, andexact description of the same. 7

The invention relates to a processfor making alloy steel, andparticularly where vanadium is employed as an alloying metal, and it isespecially useful in the production of open hearth steels.

In carrying out the invention there is mixed with the molten basicmetal, such as commercially pure steel, as it flows in a molten statefrom the furnace into the ladle a relatively small charge of a mixtureof crushed vanadium and shot or comminu-ted aluminum.

In the production of open hearth steels the furnace is provided with atap leading to the usual spout by which the molten steel is drawn oilinto the usual ladle from which it is poured into the ingot molds. Whilethe molten steel is thus being drawn oil into the ladle a small quantityof a mixture of crushed vanadium and shot aluminum is mechanicallycharged into the flowing metal in the spout, this preferably being doneby mixing a charge of the crushed vanadium andshot aluminum in a troughand discharging the mixture directly into the open top of'the spout atthe furnace tap. This mlxture is usually composed of about three partsof crushed vanadium to one part of shot aluminum, although theseproportions may be varied, and the proportion of the mixture to be usedvaries according to the character of the alloy steel desired, from 0.10%to 0.25% by weight giving satisfactory results, as a small addition ofvanadium greatly increases the tensile strength of the steel, itsmalleability, its hardness after tempering, and its fatigue resistance,while both vanadium and aluminum in small amounts deoxidize the steel.The crushed vanadium and shot aluminum may be fed into the spoutseparately though simultaneously, but in practice I prefer to mix thembefore they are supplied to the flowing metal as better results areobtained' By forming a preliminary mixture the proportions of thealloying components are more certainly ensured, and this enables them togo into the Specification of Letters Patent.

Patented June 20, 1922.

Application filed June 5, 1920. Serial No. 386,793.

steel much more accurately, besides eliminating theloss or waste of veryexpensive alloy metals. The temperature of the steel in the spout issufliciently high to instantaneously melt the added materials, of thesteel in the spout being about 3000 degrees Fahrenheit while crushedvanadium melts at about 3000 degrees Fahrenheit and shot aluminum atabout 1200 degrees Fah-. renheit, and their liquefaction is aided andhastened by the fact that they are in relatively small pieces, thevanadium being crushed into pieces ranging in size smaller than an eggand the shot aluminum being in the usual small pieces of that commercialform ofthis metal; in practice, the use of crushed vanadium and of shotaluminum as distinguished from ingot 'or bar aluminum greatly facilitatethe operation and give better results. In this form they quicklyliquefy, and the quicker melting or flash of the aluminum causes thevanadium to fuse more quickly and unite more intimately with the steelthan when the aluminum is omitted or is added in ingot form; it thenmelts at a lower temperature and acts. to more quickly liquefy thevanadium and produce a more homogeneous product.

In practice the original steel employed may be merely commercially pureor soft steel, or it may contain other alloying metals, such for exampleas nickel, depending on whether the alloy steel is to be merely vanadiumsteel or vanadium-nickel steel, and it is to be understood that myinvention comprehends such modifications and that the method of applyingit would not be modified to obtain the desired result. Further, while Iprefer to use vanadium as it deoxidizes the metal in addition to givingthe alloying qualities above mentioned, I may use other alloy metals,such for example as zirconium or titanium, which also have the propertyof cleaning up or removing oxides as well as alloying qualities toimprove the steel. In any of these variations, the alloy metal is fedinto the spout containing the molten steel in the presence of anelement, specifically shot aluminum, whichmelts or flashes at a lower.temperature or more quickly than the alloy metal and so causes thelatter to melt more quickly and to unite more intimately with the steel.

I claim:

1. The herein described step in the process of manufacturing open hearthalloy steel the temperature charging a small proportion of the mixtureinto the molten steel as the steel flows from the furnace. v

In testimony whereof I aflix my signature in the presence of twowitnesses.

JOHN MGCO'NNELL.

Witnesses J. MGROBERTS, GEORGE F. EGGERT.

